Hello forum,

I have a 2012 Discovery 4 SDV6 which suffers from “lag” when setting off from stationary. I had it mapped by Alive Tuning to resolve this issue however it didn’t appear to make much difference. I have since tried 2 new MAF sensors which also didn’t resolve the problem.

Any advice would be greatly appreciated as it’s gotten to the point where it is dangerous pulling out of junctions and I no longer have confidence driving the car.

For reference, I also have a 2015 Discovery 4 with the same engine and similar mileage however this doesn’t suffer as much as this one.

Please see the following video where the car is in “D” drive, and I take my right foot off the brake and then straight on the accelerator. You can see the car takes its time, almost crawling off the line before whoosh, it takes off like a rocket ship:



Thanks,

Ben

When my TD5 did this it was the MAP/IAT sensor.
Rolling data, or whatever it is called, on a diagnostic would prove this one way or the other.

Pull out map sensor from inlet manifold, it’s probably caked in black oily gunge, use electrical spray cleaner or similar to clean, it makes a big difference to the vehicles responsiveness